On a Microsoft Azure infrastructure, some subnet addresses are reserved for items specific to the platform. CDV will store IP addresses reserved in subnets by Azure as IP addresses with corresponding types in a BlueCat Address Manager (BAM) network. Reserved IP addresses are supported only for private virtual networks and subnets.
CDV supports the import of IPv4 reserved IP addresses for Azure. When discovering reserved IP addresses, if a specific reserved address is already used in Address Manager, CDV will log an error in the CDV error log file.
Within a subnet, Azure reserves the first four IP addresses and the last IP address, for a total of five IP addresses within each subnet CIDR block. CDV will map the reserved IP addresses to IP addresses on BAM as follows:
IPv4 networks
| Unusable address | AWS | BAM | Example |
|---|---|---|---|
| First address | Network address | Network ID | 10.1.1.0 from CIDR range 10.1.1.0/24 |
| Second address | Reserved by Azure for the default gateway | Gateway address | 10.1.1.1 from CIDR range 10.1.1.0/24 |
| Third address | Reserved by Azure to map the Azure DNS IP addresses to the virtual network space | Reserved address | 10.1.1.2 from CIDR range 10.1.1.0/24 |
| Fourth address | Reserved by Azure to map the Azure DNS IP addresses to the virtual network space | Reserved address | 10.1.1.3 from CIDR range 10.1.1.0/24 |
| Last address | Network broadcast address | Broadcast address | 10.1.1.255 from CIDR range 10.1.1.0/24 |